Why has Earth experienced ice age cycles over the past several million years? How do changes to ocean nutrients cause CO2 concentration in the atmosphere to naturally change over the course of an ice age cycle?

One of the brightest comets of the 20th century was comet hyakutake, which passed close to the sun in early 1996. the orbital period of this comet is estimated to be about 30,000 years. find the semi-major axis of this comet’s orbit. compare it to the average sun-pluto distance and to the distance to alpha centauri, the nearest star to the sun, which is 4.3 light-years distant.

All of the following occurred due to the invention of the railroad except

How many active volcanos are there in nicaragua